Respirators are worn over at least the mouth and nose of a person for two common purposes: (1) to prevent impurities or contaminants from entering the wearer's breathing tract; and/or (2) to protect others from being exposed to pathogens and other contaminants exhaled by the wearer. In the first situation, the respirator is worn in an environment where the air contains particles harmful to the wearer, for example, in an auto body shop. In the second situation, the respirator is worn in an environment where there is a high risk of infection, for example, in an operating room. To accomplish either of these purposes, a snug fit to the wearer's face must be maintained.
Respirators are commonly fit tested to determine whether they have the proper size or shape and whether they can be can be adjusted to provide an adequate seal between the respirators and the wearers' faces. Respirator fit testing has been required by various government agencies. In the United States, respirator fit testing is regulated according to 29 C.F.R. § 1910.134 (Appendix A). The regulations vary depending on the type of test being performed, for example, whether the removal efficiency of the respirator is 95%, 99%, or 99.97%.
Qualitative respirator fit testing typically involves a one-on-one test conducted by a trained test administrator on a test subject. The test subject dons a respirator and, within a controlled environment, is exposed to an aerosol that can be detected by taste or odor. The aerosols that are used in taste response testing are generated manually by a test administrator using a squeeze bulb attached to a nebulizer. The test typically involves having the test subject perform a variety of exercises, such as deep breathing, head rotation, etc., to assess the viability of the seal under conditions that may be encountered by the test subject.
Variability in respirator test results is one disadvantage of qualitative respirator fit testing. For example, the aerosol concentration levels to which the test subjects are exposed may vary if the test administrators do not manually deliver the same amount of test aerosol. Other fit testing variations may be found in the content and/or timing of prompts provided to the test subjects when directing them to perform activities as a part of the fit testing procedure.
Other disadvantages of known respirator fit testing procedures may include the cost and/or limited availability of trained personnel to carry out the tests for all of the individuals requiring them. In some instances, fit testing may be required in locations that are far removed from the location of trained test administrators. This can require travel by the test administrator or the personnel requiring fit testing to complete the required tests.